Commercially-available devices of this kind are very slow working in cold temperatures and are undependable. For example, logging equipment is often badly damaged due to mechanical failure of these devices. Engines have been known to be set on fire by some of these devices and other devices suffer from the disadvantage of being mechanically complicated and are therefore insufficiently rugged to take the abuse of the bush environment.
The object of this invention is to provide a mechanically simple engine block heater which is easy to use and which overcomes, at least in part, the aforementioned disadvantages.